Methods and apparatuses for making lithographic plates

ABSTRACT

The present invention provides methods and apparatuses for forming a mounting flange on a printing plate comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle. A bending device comprising a forming surface having a radius that is less than a desired radius for the arcuate portion can be used to form the arcuate portion in accordance with the present invention. This can be done by forming the arcuate portion to have a plurality of spaced apart bends that cooperatively define the arcuate portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application having Ser. No. 60/708,196, filed Aug. 15, 2005, entitled “METHODS AND APPARATUSES FOR MAKING LITHOGRAPHIC PLATES,” which application is incorporated herein by reference in its entirety for all purposes.

TECHNICAL FIELD

The present invention relates generally to the processing of lithographic plates. More particularly, the present invention relates to equipment for bending lithographic plates for the purpose of mounting and securing such plates on a press plate cylinder.

BACKGROUND

High-speed press operations are commonly used to print multi-color images such as those used in newspapers and the like. In such operations, individual lithographic plates are used to print the different colors found in a multi-color image. Such multi-color images therefore comprise a superimposed color image. The lithographic plates are carefully mounted on a printing press with respect to each other so that the individual color images formed on the printed surface are sufficiently registered to provide the desired clarity and sharpness in the final superimposed image. Otherwise, the final image can have ghost-like characteristics as a result of any plate misalignment.

A typical lithographic plate includes features such as flanges and openings that enable it to be mounted on a printing plate cylinder of a printing press. The configuration of these flanges and openings defines the alignment between plural plates installed on a printing press and provides the registration of the various colors of the printed image. Accordingly, precision metal working techniques for bending such flanges and forming such openings are used to ensure precision alignment between plural plates mounted on a printing press.

A typical machine used for forming a precision bend in a lithographic plate includes an anvil provided at the end of a supporting surface, a clamping device for clamping a plate to be bent to the supporting surface, and a mandrel for bending the plate around the anvil to form a flange. The anvil has an end with a forming surface that has a predetermined radius and a bend is made by rolling the plate around the radius of the forming surface of the anvil. In this way, the material of the plate conforms to the shape of the anvil to form a bend radius in the flange that is defined by the radius of the forming surface of the anvil. Machine tools for bending lithographic plates are described in U.S. Pat. No. Re. 31,938, reissued Jul. 9, 1985, to Klukow, U.S. Pat. No. 5,970,774 to Burgess et al., and U.S. Pat. No. 5,454,247 to Powers et al., the disclosures of which are incorporated herein by reference in their entirety for all purposes.

Lithographic plate bending machines, as presently known, suffer from certain limitations. Printing presses manufactured by different companies have lithographic plate receiving slots that require lithographic plates with mounting flanges having angles and bend radiuses different than those of other manufacturers. This requires the printer to either have multiple benders each with an anvil having an angle and radius unique to the printing press on which the lithographic plate is to be mounted or to remove and replace the anvils each time a lithographic plate is to be bent for a different printing press.

SUMMARY

The present invention provides bending apparatuses and methods that can form lithographic plates for different printing press configurations without the need to use different anvils. In this regard, a single bending apparatus can be used to form lithographic plates having different configurations for printing presses made by different manufacturers. Methods and apparatuses in accordance with the present invention include forming a mounting flange on a printing plate. The mounting flange comprises first and second portions having an arcuate portion therebetween that defines a mounting flange angle. A bending device comprising a forming surface having a radius that is less than a desired radius for the arcuate portion can be used to form the arcuate portion in accordance with the present invention. This can be done by forming the arcuate portion to have a plurality of spaced apart bends that cooperatively define the arcuate portion.

In one aspect of the present invention a method of forming a mounting flange on a printing plate is provided. The mounting flange comprises first and second portions having an arcuate portion therebetween and defining a mounting flange angle. Generally, the method comprises the steps of defining a desired radius for the arcuate portion of the mounting flange, providing a bending device, and forming a plurality of spaced bends in the printing plate. In accordance with the present invention, the bending device comprises a forming surface having a radius selected to be less than the desired radius for the arcuate portion of the mounting flange. Each of the spaced bends is defined by the radius of the forming surface of the bending device wherein the plurality of spaced bends cooperatively define the desired bend radius for the arcuate portion of the mounting flange.

In another aspect of the present invention a method of forming a mounting flange on a printing plate is provided and includes moving a forming surface of a bending device relative to the printing plate to form a plurality of spaced bends. The mounting flange comprises first and second portions having an arcuate portion therebetween and defining a mounting flange angle. Generally, the method comprises the steps of defining a desired radius for the arcuate portion of the mounting flange, providing a bending device, and forming the arcuate portion in the printing plate. In accordance with the present invention, the bending device comprises a forming surface having a radius selected to be less than the desired radius for the arcuate portion of the mounting flange. The step of forming the arcuate portion of the mounting flange comprises positioning the forming surface of the bending device in a predetermined position relative to the printing plate, forming a first bend at a predetermined location in the printing plate wherein the first bend is defined by the radius of the forming surface of the bending device, and spacing the forming surface of the bending device relative to the first bend and forming at least one additional bend spaced from the first bend wherein the first bend and the at least one additional bend spaced from the first bend cooperatively define the desired bend radius for the arcuate portion of the mounting flange.

In another aspect of the present invention, an apparatus for forming a mounting flange on a printing plate is provided. The mounting flange comprises first and second portions having an arcuate portion therebetween and defining a mounting flange angle. The apparatus comprises a bending device that includes a supporting bed, an anvil and mandrel arrangement, means for selectively varying the relative position of the forming surface of the anvil of the bending device and a predetermined portion of a printing plate when positioned on the support surface, and a control system. The anvil comprises a forming surface having a predetermined radius and the mandrel is positioned relative to the forming surface of the anvil. The mandrel is capable of being controllably rotated about the forming surface of the anvil to bend a printing plate when positioned on the supporting surface. In accordance with the present invention, the control system comprises programming instructions that can direct the bending device to form a plurality of spaced bends in a printing plate. Each of the spaced bends is defined by the radius of the anvil of the forming surface of the bending device. The plurality of spaced bends cooperatively define a desired radius for the arcuate portion of the mounting flange and the desired radius of the arcuate portion is larger than the radius of the forming surface of the anvil of the bending device.

In yet another aspect of the present invention, a printing plate that can be mounted on a plate cylinder of a printing press is provided. The printing plate comprises a mounting flange comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle. The arcuate portion has a radius and comprises a plurality of spaced bends that cooperatively form the radius of the arcuate portion. Each individual bend of the plurality of bends has a radius less than the radius of the arcuate portion.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

FIG. 1 is a top view of a printing plate that can be formed in accordance with the present invention comprising a mounting flange at each of leading and trailing ends of the printing plate for mounting the printing plate to a plate cylinder of a printing press;

FIG. 2 is an end view of the printing plate of FIG. 1;

FIG. 3 is a side view of the printing plate of FIGS. 1 and 2;

FIG. 4 is an enlarged detail view of the mounting flange of the leading edge of the printing plate of FIGS. 1-3 showing the mounting flange as comprising a body portion of the printing plate, a flange portion at the end of the plate making an angle with the body portion, and an arcuate portion between the body portion and the flange portion comprising a plurality of spaced bends in accordance with the present invention;

FIG. 5 is a schematic view of a processing system for making a printing plate in accordance with the present invention, the processing system as shown comprising an exposing device, a developing device, and a bending machine;

FIG. 6 is a schematic view of a bending machine usable in the system of FIG. 5, showing a printing plate positioned relative to an anvil having a forming surface with a predetermined radius, a clamping device, and a mandrel wherein the clamping device is in a clamping position and the mandrel is positioned ready to form a bend in the printing plate in accordance with the present invention;

FIG. 7 is a schematic view of the bending machine shown in FIG. 6 showing the clamping device in the clamping position and the mandrel rotated to a position that forms a first bend in the printing plate around a portion of the predetermined radius of the anvil in accordance with the present invention;

FIG. 8 is a schematic view of the bending machine and printing plate of FIG. 7 showing the clamping device in the clamping position and the mandrel rotated back to the ready position after forming the first bend in the printing plate;

FIG. 9 is a schematic view of the bending machine and printing plate of FIG. 8 showing the clamping device and mandrel in retracted positions;

FIG. 10 is a schematic view of the bending machine and printing plate of FIG. 9 showing the anvil, clamping device, and mandrel spaced from the first bend at a position for forming a second bend spaced from first bend in accordance with the present invention;

FIG. 11 is a schematic view of the bending machine and printing plate of FIG. 10 showing the clamping device in the clamping position and mandrel in a ready position in preparation of a second bend;

FIG. 12 is a schematic view of the bending machine shown in FIG. 11 showing the mandrel rotated to a position that forms the second bend in the printing plate around a portion of the radius of the anvil in accordance with the present invention;

FIG. 13 is a schematic view of the bending machine and printing plate of FIG. 12 showing the clamping device and mandrel in the clamping position after forming the second bend in the printing plate;

FIG. 14 is a schematic view of the bending machine of FIG. 12 showing a printing plate comprising an arcuate portion comprising a plurality of spaced bends in accordance with the present invention each of which can be made as shown in FIGS. 6-13 by repeating the steps of translating the anvil, clamp, and mandrel and moving the mandrel about an axis of rotation;

FIG. 15 is a schematic side view of a bending machine comprising first and second bending units at opposite ends of the bending machine for forming mounting flanges at first and second opposite ends of a printing plate in accordance with the present invention;

FIG. 16 is an exploded perspective view of the second bending unit of the bending device of FIG. 15; and

FIG. 17 is a side view of the bending unit shown in FIG. 16.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, an exemplary printing plate 10 that can be made in accordance with the present invention is shown. The printing plate 10 generally comprises a leading edge 12, a trailing edge 14, and first and second sides, 16 and 18. As shown, the printing plate 10 comprises a first mounting flange 20 at the leading edge 12 and a second mounting flange 22 at the trailing edge 14 that are used to mount the printing plate 10 to a plate cylinder of a printing press when used in a printing operation. The first mounting flange 20 is defined by a flange portion 24, an arcuate portion 26, and a body portion 28 of the printing plate 10. The body portion 28 provides a main section to receive an image as described below. The arcuate portion 26 defines a mounting flange angle α between the flange portion 24 and the body portion 28. Similarly, the second mounting flange 22 is defined by a flange portion 30, an arcuate portion 32, and the body portion 28 of the printing plate 10. The arcuate portion 32 defines a mounting flange angle β between the flange portion 30 and the body portion 28.

Preferably, the first mounting flange 20 includes an alignment notch 34 and the second mounting flange 22 includes an alignment notch 36. The alignment notches 34 and 36 are used to align the printing plate 10 in a lateral or side-to-side manner when mounted on a plate cylinder of a printing press as conventionally known. The printing plate 10 also comprises an image 38 provided on a surface 40 of the body portion 28 of the printing plate 10. The image 38 preferably comprises first and second fiducial marks, 42 and 44, that can be used to align the image 38 on the printing plate 10 with an image on another printing plate such as when printing a composite color image, for example. The printing plate 10 may also include indicia (not shown) in the form of a bar code or other mark or means of identifying the printing plate 10. Such indicia can be used to identify a particular page of a newspaper or the like to be printed by the printing plate 10, for example.

Referring to FIG. 4, the exemplary mounting flange 20 of the printing plate 10 is shown in greater detail. Methods for forming the mounting flange 20 are described in detail below. As illustrated, the arcuate portion 26 comprises spaced bends 50, 52, and 54 and may have any number of spaced bends having the same or different individual radiuses. The arcuate portion 26 also comprises a linear portion 51 between the bends 50 and 52 and a linear portion 53 between the bends 52 and 54. The length of a linear portion is defined by the spacing of the bends. In this regard, spaced bends may be equally spaced or differently spaced. The arcuate portion 26 extends from the body portion 28 starting at first bend 50 and the flange portion 24 extends from the arcuate portion 26 starting from last bend 54. Thus, the body portion 28 and the flange portion 24 make the mounting flange angle α between the flange portion 24 and the body portion 28. In use, the mounting flange angle α corresponds with the design of the particular printing press that the printing plate 10 is to be mounted to.

The bend 50 has a radius R1, the bend 52 has a radius R2, and the bend 54 has a radius R3. As illustrated, the radiuses R1, R2, and R3 are nominally equal meaning that the radiuses R1, R2, and R3 are preferably defined by the same forming surface as described in more detail below. Together, the radiuses R1, R2, and R3 of the spaced bends 50, 52, and 54 define a bend radius R4 for the arcuate portion 26 which preferably corresponds with the design of the particular printing press that the printing plate 10 is to be mounted to. Because the bends 50, 52, and 54 are spaced by the linear portions 51 and 53, the bend radius R4 of the arcuate portion 26 is not a true geometric radius and can be thought of as an effective bend radius.

With reference to FIG. 5 an exemplary system 100 that can be used to make the printing plate 10 in accordance with the present invention is schematically shown. Generally, as illustrated, the system 100 comprises an exposing device 104, a developing device 106, and a bending machine 108. Typically, the printing plate 10 is transferred to the exposing device 104 where the printing plate 10 is precisely positioned relative to an overlying film. The printing plate 10 is then exposed through the film, which has an image thereon, and which image is transferred to the printing plate 10 to form the image 38 on the printing plate 10.

After the printing plate 10 is exposed, it is chemically treated by the developing device 106 in a conventional manner and then transferred to the bending machine 108. The bending machine 108 then functions to bend the plate 10 to form the first and second flanges 20 and 22. In accordance with one aspect of the present invention, this can be done in such a way that a printing plate, such as the printing plate 10, can be formed to fit the particular press on which it is to be mounted without being limited by a specific radius of an anvil of the bending machine 108 as described in detail below. Different printing presses can have different mounting requirements including bend radiuses, flange angles, flange lengths, for example. The bending machine 108 can be used to make printing plates for such different mounting requirements as described below without having to retool the bending machine as is conventionally done. Another exemplary system that can be used to make the printing plate 10 is described in U.S. Pat. No. 5,502,993 to Powers et al., the entire disclosure of which is incorporated herein by reference for all purposes.

In FIGS. 6-14, one end of the bending machine 108 is shown schematically and a portion of printing plate 110 is shown at various stages of the formation of a mounting flange 112. In FIG. 14, mounting flange 112 is illustrated and comprises a body portion 114 of the printing plate 110, an arcuate portion 116, and a flange portion 118 at an angle α to the body portion 114. In this way, the mounting flange 112 is similar to the mounting flange 20 described above with respect to FIG. 4. As illustrated, the bending machine 108 comprises an anvil 120, a clamping device 122, and a mandrel 124. The anvil 120 comprises a forming surface 126 having a predetermined radius. The clamping device 122 is capable of holding the body portion 114 of the printing plate 110 relative to the anvil 120 while the mandrel 124 is rotated about the forming surface 126 of the anvil 120 as set forth in more detail below. Bending devices that use an anvil, clamp, and mandrel are well known. For example, such bending devices are described in U.S. Pat. No. Re. 31,938, reissued Jul. 9, 1985, to Klukow, U.S. Pat. No. 5,970,774 to Burgess et al., and U.S. Pat. No. 5,454,247 to Powers et al. and are fully incorporated by reference herein for all purposes.

In FIG. 6, the printing plate 110 is shown positioned relative to the anvil 120 with the clamping device 122 shown functionally holding the printing plate 110 against the anvil 120 and with the mandrel 124 in an engaged position ready to form a bend in the printing plate 110. Specifically, as illustrated, an end 128 of the printing plate 110 is spaced from the forming surface 126 of the anvil 120 by a predetermined distance.

In FIG. 7, the mandrel 124 is shown rotated about the forming surface 126 of the anvil 120 to form a first bend 130 in the printing plate 110 in accordance with the present invention. As described below, additional bends are formed which together can define the arcuate portion 116 of the mounting flange 112 shown in FIG. 14. The first bend 130 is formed so that the flange portion 118 makes an angle 132 with the body portion 114. The angle 132 can be determined as based on the desired geometry for a particular mounting flange to be formed, the material thickness, and the radius of the forming surface 126, for example. In FIG. 8, the mandrel 124 is shown rotated back to the position shown in FIG. 6 after the first bend 130 is formed.

In FIG. 9, the clamping device 122 and the mandrel 124 are each shown in a retracted position. In accordance with the present invention, the forming surface 126 of the anvil 120 can be spaced from the first bend 130 by a predetermined distance 134, as illustrated, to form an additional bend spaced from the first bend 130 as discussed below. The distance 134 relates to the geometry of the particular mounting flange to be formed and contributes to defining the bend radius of an arcuate portion of a mounting flange in accordance with the present invention. Preferably, the printing plate 110 remains stationary and the anvil 120 is retracted along a machine direction 136 as shown in FIG. 10. However, the printing plate 110 can be moved or otherwise advanced relative to a stationary anvil to achieve the same result. Also, both the printing plate 110 and the anvil 120 can be moved relative to each other to position the forming surface 126 of the anvil 120 relative to the first bend 130.

In FIG. 11, the printing plate 110 is shown positioned relative to the anvil 120 with the clamping device 122 shown functionally holding the printing plate 110 against the anvil 120 and with the mandrel 124 in an engaged position ready to form another bend spaced from the first bend 130 in the printing plate 110. In FIG. 12, the mandrel 124 is shown rotated about the forming surface 126 of the anvil 120 to form a second bend 138 in the printing plate 110 that is spaced from the first bend 130 in accordance with the present invention. The second bend 138 is formed so that a first linear portion 140 makes an angle 142 with the body portion 114. The angle 142 is preferably similar to the angle 132 of the first bend 130 and can be determined as based on the desired geometry for a particular mounting flange to be formed as discussed above. The angles 132 and 142 do not need to be similar and can be different. In FIG. 13, the mandrel 124 is shown rotated back to the position shown in FIG. 11 after the second bend 138 is formed.

The process described above for forming the first and second bends 130 and 138 can be repeated as many times as desired to form a mounting flange having any desired geometry in accordance with the present invention. For example, as shown in FIG. 14, the arcuate portion 116 of the mounting flange 112 comprises the first and second spaced bends, 130 and 138, as well as spaced bends 144, 146, and 148, which are preferably similarly formed. The arcuate portion 132 also comprises linear portions 150, 152, and 154, as shown, which are preferably similar to the linear portion 140 described above. The arcuate portion 116 of the mounting flange 112 is exemplary and may comprise any number of spaced bends and corresponding linear portions between spaced bends. The number of spaced bends and the distance between spaced bends for a particular mounting flange of a printing plate can be determined based on factors including, but not limited to, the desired effective radius for an arcuate portion of the mounting flange, the radius of a forming surface of an anvil of a bending device, the desired mounting flange angle, the type of material for the printing plate, the material thickness, and the minimum bend radius for the particular material used, for example.

In FIGS. 15-17, an exemplary bending device 150 that can be used as the bending machine 108 is shown. In FIG. 15 the bending device 150 is shown schematically and in FIGS. 16 and 17 the bending device 150 is shown in greater detail.

Referring to FIG. 15, the bending device 150 comprises a table 152 having a printing plate 154 supported thereon and first and second bending units, 156 and 158, positioned relative to the table 152 for forming first and second mounting flanges, 160 and 162, of the printing plate 154 in accordance with the present invention as described above. As shown, the first bending unit 156 comprises an anvil 164 that is movable along a machine direction 166, a mandrel 168 that is movable about the anvil 164 for forming the flange 160, and a clamping device 170 that can hold the printing plate 154 during a bending operation. Similarly, the second bending unit 158, as shown, comprises an anvil 172, a mandrel 174, and a clamping device 176 that preferably function in the same manner as the anvil 164, mandrel 168, and clamping device 170.

In FIGS. 16 and 17, the bending unit 158 is shown in greater detail. The bending unit 156 is preferably similar to the bending unit 158. The bending unit 158 is shown in a perspective view in FIG. 16 and a side view in FIG. 17. Referring to FIG. 16, the bending unit comprises a beam 178 that supports spaced support structures 180 (shown in phantom line) and 182 that functionally support the anvil 172, mandrel 174 and clamping device 176, as illustrated.

The mandrel 174 and clamping device 176 are designed so that they can be translated in a direction 184 generally perpendicular to the machine direction 166. In this way the clamping device 176 can clamp a printing plate to the anvil 172 during a bending operation. In order to function this way, the support structure 182, as shown, comprises a bracket 186 that supports the clamping device 176. The bracket 186 is slidably mounted to a shaft 188, as illustrated, and driven by a linear drive device 190 such as a pneumatic cylinder or the like that is mounted to the support structure 182. Preferably, the support structure 182 supports the clamping device 176 with a similar bracket drivable by a drive device 192 mounted to the support structure 182, as shown.

The mandrel 174 is mounted to the bracket 186 so that it can be translated together with the clamping device 176 in the direction 184 and so that it can controllably pivot with respect to the bracket 186 to bend a mounting flange in accordance with the present invention. As shown, the mandrel 174 is pivotably mounted to the bracket 186 with pivot plate 194. The mandrel 174 is also pivotably mounted to a bracket (not shown) of the support device 180 that is preferably similar to the bracket 186 by a pivot plate 196. The pivot plate 196 is functionally connected to a timing pulley 198. The timing pulley 198 can be driven by a drive pulley 200 of a servo motor 202 by a drive belt (not shown). This drive arrangement also includes an idler pulley 204, as shown. The illustrated pulley and motor drive arrangement is exemplary and any known or future developed device that can function to controllably pivot the mandrel 174 for bending a flange of a printing plate in accordance with the present invention can be used.

Preferably, the bending unit 158 is designed so that the bending unit 158 can be controllably translated along the machine direction 166. For example, the beam 178 can be supported by rails or slides (not shown) as supported by a support structure or frame or the like (not shown). As can be seen in both FIGS. 16 and 17, the bending unit 158 includes a lead screw assembly 206 that is preferably mounted to the support structure that supports the rails or slides (not shown). As illustrated, the lead screw assembly 206 comprises a lead screw 208 and a ball nut 210 attached to the beam 178. The bending unit 158 also comprises a servo motor 212 that includes a drive pulley 214 that can drive a pulley 216 of the lead screw 208 as connected by a belt (not shown). In this way the bending unit 158 can be controllably positioned relative to a printing plate for bending a mounting flange in accordance with the present invention. Preferably, the drive cylinders, 190 and 192, and the servo motors 202 and 212 are controlled by a control system (not shown). The control system preferably includes programming instructions such as software or code or the like that is designed to direct or control the motion of the various movable components of a bending device.

The present invention has now been described with reference to several embodiments thereof. The entire disclosure of any patent or patent application identified herein is hereby incorporated by reference. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. It will be apparent to those skilled in the art that many changes can be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures described herein, but only by the structures described by the language of the claims and the equivalents of those structures. 

1. A method of forming a mounting flange on a printing plate, the mounting flange comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle, the method comprising the steps of: defining a desired radius for the arcuate portion of the mounting flange of the printing plate; providing a bending device comprising a forming surface having a radius selected to be less than the desired radius for the arcuate portion of the mounting flange; and forming a plurality of spaced bends in the printing plate with the bending device, each of the spaced bends defined by the radius of the forming surface of the bending device wherein the plurality of spaced bends cooperatively define the desired bend radius for the arcuate portion of the mounting flange.
 2. The method of claim 1, wherein the desired radius for the arcuate portion of the mounting flange is selected based on a minimum bend radius for the material type and thickness of the printing plate.
 3. The method of claim 1, wherein the step of forming a plurality of spaced bends comprises positioning the forming surface of the bending device relative to a predetermined location of the printing plate and forming a first bend in the printing plate at the predetermined location.
 4. The method of claim 3, comprising spacing the forming surface of the bending device from the first bend and forming a second bend in the printing plate.
 5. The method of claim 4, comprising forming at least one additional bend in the printing plate by spacing the forming surface of the bending device from a previously formed bend and forming the at least one additional bend.
 6. The method of claim 1, comprising forming an image on the printing plate before forming the plurality of spaced bends in the printing plate.
 7. A method of forming a mounting flange on a printing plate, the mounting flange comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle, the method comprising the steps of: defining a desired radius for the arcuate portion of the mounting flange of the printing plate; providing a bending device comprising a forming surface having a radius selected to be less than the desired radius for the arcuate portion of the mounting flange; and forming the arcuate portion of the mounting flange by: positioning the forming surface of the bending device in a predetermined position relative to the printing plate; forming a first bend at a predetermined location in the printing plate wherein the first bend is defined by the radius of the forming surface of the bending device; and spacing the forming surface of the bending device relative to the first bend and forming at least one additional bend spaced from the first bend wherein the first bend and the at least one additional bend spaced from the first bend cooperatively define the desired bend radius for the arcuate portion of the mounting flange.
 8. The method of claim 7, wherein the step of spacing the forming surface of the bending device relative to the first bend comprises retracting the forming surface of the bending device relative to the first bend while the printing plate is stationary.
 9. The method of claim 7, wherein the step of spacing the forming surface of the bending device relative to the first bend comprises advancing the first bend of the printing plate relative to the forming surface of the bending device while the forming surface of the bending device is stationary.
 10. The method of claim 7, wherein the step of spacing the forming surface of the bending device relative to the first bend comprises moving both the forming surface of the bending device and the printing plate relative to each other.
 11. An apparatus for forming a mounting flange on a printing plate, the mounting flange comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle, the apparatus comprising: a bending device, the bending device comprising: a supporting bed; an anvil comprising a forming surface having a predetermined radius and a mandrel positioned relative to the forming surface of the anvil, the mandrel capable of being controllably rotated about the forming surface of the anvil to bend a printing plate when positioned on the supporting surface; and means for selectively varying the relative position of the forming surface of the anvil of the bending device and a predetermined portion of a printing plate when positioned on the support surface; and a control system comprising programming instructions that can direct the bending device to form a plurality of spaced bends in a printing plate, each of the spaced bends defined by the radius of the anvil of the forming surface of the bending device wherein the plurality of spaced bends cooperatively define a desired radius for the arcuate portion of the mounting flange and wherein the desired radius of the arcuate portion is larger than the radius of the forming surface of the anvil of the bending device.
 12. The apparatus of claim 11, wherein the means for selectively varying the relative position of the forming surface of the anvil of the bending device and a predetermined portion of a printing plate comprises a motor that can move the anvil under the control of the control system.
 13. The apparatus of claim 11, wherein the means for selectively varying the relative position of the forming surface of the anvil of the bending device and a predetermined portion of a printing plate comprises a conveyor that can move the printing under the control of the control system.
 14. The apparatus of claim 11, wherein the programming instructions of the control system include an algorithm that can design the arcuate portion of the mounting flange as based on information comprising the radius of the forming surface of the anvil and a desired mounting flange angle.
 15. A printing plate that can be mounted on a plate cylinder of a printing press, the printing plate comprising a mounting flange comprising first and second portions having an arcuate portion therebetween and defining a mounting flange angle, the arcuate portion having a radius and comprising a plurality of spaced bends that cooperatively form the radius of the arcuate portion, each individual bend of the plurality of bends having a radius less than the radius of the arcuate portion.
 16. The printing plate of claim 15, wherein the arcuate portion of the mounting flange has a radius equal to or greater than a minimum bend radius for the material type and thickness of the printing plate.
 17. The printing plate of claim 15, wherein each of the spaced bends of the plurality of spaced bends are equally spaced from each other.
 18. The printing plate of claim 15, wherein the arcuate portion comprises a plurality of spaced bends and spaced linear portions alternating with respect to each other.
 19. The printing plate of claim 15, comprising at least one additional mounting flange.
 20. The printing plate of claim 15 in combination with a printing press. 